Using simple volumes

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Using simple volumes

A simple volume is a portion of a physical disk that functions as though it were a physically separate unit. Simple volumes are the dynamic storage equivalent of primary partitions in Windows NT 4.0 or earlier. When you have only one dynamic disk, they are the only kind of volume that you can create.

You can create simple volumes only on dynamic disks. Simple volumes (and the data they contain) cannot be accessed by, or created on, computers running MS-DOS, Windows 95, Windows 98, Windows Millennium Edition, Windows NT 4.0, or Windows XP Home Edition that are configured to dual-boot with Windows XP Professional or Windows Server 2003 operating systems. If you want computers running these operating systems to be able to access the data, store the data on basic volumes.

You can increase the size of an existing simple volume by extending the volume onto unallocated space on the same disk or a different disk. To extend a simple volume, the volume must be unformatted or formatted with the version of NTFS used in Windows 2000 or Windows Server 2003 operating systems. With Windows Server 2003, simple volumes can be extended unless they are system partitions, boot partitions, or simple volumes that were formerly partitions on basic disks that were converted to dynamic using Windows 2000. By extending the simple volume on the same disk, the volume remains a simple volume and you can still mirror it.

You can also extend a simple volume to regions on other dynamic disks on the same computer. When you extend a simple volume to one or more other disks, it becomes a spanned volume. After a spanned volume is extended, no portion of it can be deleted without deleting the entire spanned volume. Spanned volumes cannot be mirrored.

For procedures on creating and extending simple volumes, see Manage Simple Volumes.

Assigning drive letters

You can create more than 26 volumes with Windows, but you cannot assign more than 26 drive letters for accessing these volumes. Drive letters A and B are typically reserved for floppy disk drives. If the computer does not have a floppy disk drive, you can assign drive letters A and B to removable drives, hard disk drives, or mapped network drives. Hard disk drives are typically assigned drive letters C through Z, while mapped network drives are assigned drive letters in reverse order (Z through C).

You should be careful when making drive-letter assignments because many programs for MS-DOS and Windows make references to a specific drive letter. The path environment variable shows specific drive letters with program names.

Volumes created after the 26th drive letter has been used must be accessed using volume mount points, as described in Using NTFS mounted drives.

Formatting and labeling volumes

Before you can store files and directories on the volumes that you have created, you must first format each volume for use with the file system that you want to work with. You can also assign descriptive volume labels at this time.

If a volume uses NTFS formatting, you can enable data compression. Before you can format a volume, you must assign it either a drive letter or a mount point, if it does not already have one.

To format a volume, see Format a dynamic volume.

Deleting volumes

Before deleting volumes, you need to make sure the information on them has been backed up onto another storage medium and verified, or that the data is no longer needed. Windows XP and Windows Server 2003 operating systems do not allow you to delete the system volume or boot volume.